In the industrial fields related to medicines, agrochemicals, and biochemicals, it is an extremely important problem to separate/purify a target substance to be produced, and methods using separating agents have been conventionally employed as techniques for such separation. Examples of principles on which a substance to be separated is separated using such separating agents include one in which affinity between a separating agent and a target substance is utilized, and one in which the optical activity of both a separating agent and a target substance is utilized.
Separating agents, in which wholly porous silica gel is used as a support and various ligands are fixed to the support in accordance with a target substance to be separated, are conventionally known as such separating agents.
Known as such a separating agent obtained using wholly porous silica gel as a support is, for example, a separating agent containing an optically active polymer fixed therein. In the case of using such a separating agent in which an optically active polymer is fixed to a support, optical resolution can be performed.
Having been reported as the optically active polymer are polysaccharide derivatives derived from polysaccharides such as cellulose (see, for example, patent document 1), optically active poly(meth)acrylamides (see, for example, patent document 2), optically active poly(amino acid)s (see, for example, patent document 3), and optically active polyamides (see, for example, patent documents 4 and 5).
Meanwhile, a separating agent for optical isomers is also known in which an optically active low-molecular-weight compound (e.g., a compound having a binaphthyl structure or crown ether structure) is bonded to a support by chemical bonding (see, for example, patent document 6).
Furthermore reported is a separating agent which contains, as a support, particles constituted of a synthetic polymer having a crosslinked structure and further contains, as a ligand fixed thereto, either a protein or a glycoprotein having a sugar chain (see, for example, patent document 7).
With respect to separating agents obtained by fixing a nucleic acid to a support, a technique in which DNA is immobilized to a glass substrate through chitosan is, for example, known (see, for example, patent document 8).
Moreover, with respect to chips for use in identifying ionic polymers, a technique in which DNA, RNA, or the like is fixed to a support such as glass is also known (see, for example, patent document 9).
Wholly porous silica gel has conventionally been used as a support to be used for fixing ligands thereto. Regarding this, also known besides such wholly porous particles are core/shell particles each including a nonporous core and a porous shell covering the outer surface thereof (see, for example, patent document 10). Also known is a separating agent for optical isomers which is obtained by fixing cellulose tris(4-chloro-3-methylphenylcarbamate) to such core/shell particles which have a pore diameter of 10 nm (for example, non-patent document 1).
Patent Document 1: WO 2008/102920
Patent Document 2: WO 02/088204
Patent Document 3: Japanese Patent Application Laid-open No. H10-128089
Patent Document 4: Japanese Patent Application Laid-open No. H11-335306
Patent Document 5: Japanese Patent Application Laid-open No. 2009-91535
Patent Document 6: Japanese Patent Application Laid-open No. 2003-327675
Patent Document 7: Japanese Patent Application Laid-open No. 2012-18135
Patent Document 8: Japanese Patent Application Laid-open No. 2010-77022
Patent Document 9: Japanese Patent Application Laid-open No. 2003-284552
Patent Document 10: Japanese Patent Application Laid-open No. S49-36396
Patent Document 11: Japanese Examined Patent Publication No. H4-077737
Non-patent document 1: K. Lomsadze, G. Jibuti, T. Farkas, B. Chankvetadze, J. Chromatogr. A 1234 (2012) 50
Non-patent document 2: B. Chankvetadze, E. Yashima, Y. Okamoto, J. Chromatogr. A 670 (1994) 39
Non-patent document 3: Y. Okamoto, M. Kawashima, K. Hatada, J. Chromatogr. 363 (1986) 173
Non-patent document 4: Y. Okamoto, R. Aburatani, K. Hatada, Bull. Chem. Soc. Jpn. 63 (1990) 955
Non-patent document 5: B. Chankvetadze, E. Yashima, Y. Okamoto, J. Chromatogr. A 694 (1995) 101
Non-patent document 6: Y. Okamoto, R. Aburatani, T. Fukumoto and K. Hatada, Chem Lett., (1987) 1857